How Experience in WWI brought the U.S. Army to Victory in WWII

We’re in the early months of the centennial of U.S. participation in World War I, the so-called, “War to end all wars.” With the vantage of 20/20 hindsight, we now know that rather than “making the world safe for democracy,” as Woodrow Wilson hoped, World War I instead set the stage for the next round of global conflict. The United States entered the war in 1917 as a relatively unknown quantity. The U.S. Army was tiny in 1917, and many wondered whether it would be able to mobilize enough men to really make a difference. In the end, the U.S. was able to put over a million military personnel in Europe – enough to sway the balance of power in Europe against the Central Powers. November of 1918 saw the Armistice signed and a tenuous peace return to the world. And suddenly, America felt and saw the power of her military might. This came at the cost of hundreds of thousands of killed, wounded, and missing servicemen.

After the initial euphoria of victory wore off, Americans began to ask what had been gained from the war. As the Great Depression swept the world and Germany slid towards totalitarianism, this question became all the more pertinent. When war flared again in 1939, one can hardly blame those who advocated for U.S. isolationism given that U.S. participation in the Great War seemingly did little to prevent another conflagration. But what these people didn’t realize was that America would win World War II because of their experience in World War I.

When the U.S. entered World War I in 1917, the Army more closely resembled that of the Civil War than that of World War II. The horse was still the prime mover for the majority of the Army. The National Guard was still organized in state entities with no division alignments, ill-suited for modern warfare. The Army had few effective machine guns and virtually no modern artillery. There were no tanks or aircraft. Thus it was that machine guns, automatic rifles, gas masks, grenades, artillery, tanks, and aircraft all had to be supplied by the French and British in the first year of U.S. participation in the war.

While the equipment and organization of the Army lagged behind the rest of the world in 1917, there were greater and more serious gaps at the strategic level. Very few leaders had commanded or maneuvered anything larger than a brigade. Now the Army was designing divisions of 28,000 men – a massive and unwieldy organization. The Army would struggle to keep command and control across these huge units throughout the entirety of the war. There was very little concept of command and staff operations in the U.S. Army at the strategic level at the outset of the war. And the man chosen to lead the new American Expeditionary Force had some strong ideas about warfare that did not mesh with the realities on the battlefields of Europe. General John J. Pershing stated that, “the ultimate success of the army depends upon their proper use in open warfare…Aggressive offensive based on self-reliant infantry.” In other words, Pershing said that movement and maneuver in the open would be the foundation of U.S. tactics rather than the trench warfare of literally everyone else.

There was a problem with this, of course. The French and British had been trying this for years – with calamitous results. In fact, just as the U.S. was entering the war, the French were annihilating a large part of their army in the Nivelle Offensive. The enormous losses they incurred from this operation caused whole divisions to mutiny. This led to massive reforms within the French Army. The Germans were already moving toward infiltration tactics. All sides were experimenting with combined arms with tanks, airplanes, artillery, and infantry working together. And here came the Americans, scoffing at the battle-hardened British and French, saying that trench warfare had made them immobile and scared to attack. As one American brigade commander told his men in 1917, “The war will be won in the open; the Boche is in the trenches now and has been for four years. We have got to be able to drive him out and that is why this French instruction is valuable; but remember we are going to get him out into the open and then all the old and fixed principles of our school of warfare will come into play.” In the first American offensives of 1918 at Cantigny and Chateau-Thierry, thousands of Americans died in droves in front of German machine guns and under bursting artillery shells. Divisions were cleaned out in weeks and had to be revitalized with barely-trained replacements. It was an unsustainable form of warfare.

Throughout 1918, the Americans struggled to adapt their tactics to their adversaries. They fielded tanks at St. Mihiel, built up a formidable Air Service, and slowly learned how to fight war in the 20th century. Pershing and his staff began to learn that prosecuting war on the battlefield was not the only fight; as important was negotiating with allies. Unfortunately, Pershing was not a man cut out for diplomacy. While he certainly looked the part, he lacked the temperament for dealing with his British and French counterparts – with whom he clashed constantly. To his credit, he had been placed in an incredibly difficult situation: raise, arm, train, and field the largest American army ever created while staving off British and French attempts to take all his troops for their own offensives. But he didn’t make it easier on himself by blowing up at his allied counterparts and creating what could have been international incidents, had the Allies not needed American assistance so badly. Fortunately, he had some good subordinates, such as George C. Marshall. It was Marshall who not only organized and planned the Meuse-Argonne Offensive – the war-ending battle – but who smoothed over Pershing’s relations with everyone from foreign generals to Pershing’s own irate division commanders who objected to his micromanagement.

It was junior officers – men like Marshall, George Patton, Douglas MacArthur, Dwight Eisenhower (although he was never afforded the opportunity to fight in Europe), Mark Clarke, Lesley McNair, and Walter Kruger, amongst so many – who looked at the lessons from World War I and realized that the U.S. Army needed to change if it wanted to be competitive on the battlefield in another war. They knew that the Army could not sustain the disastrous casualty rates that “open warfare” had caused.

So they began to change the Army after the World War. Change was slow because they were still fighting the general officers who had grown up in the pre-World War I Army. Patton and Eisenhower were threatened with court martial if they didn’t stop publishing articles about such heretical things as the tank being the basis for offensives rather than dismounted infantry. Efforts of the World War I generation were not helped by popular distrust in the military as the Army battled small budgets, low manpower authorizations, and increasing responsibilities around the world. Marshall moved his way through the Army staff system, overseeing sweeping changes to doctrine and staff procedures. By 1939, he was the Army Chief of Staff; the WWI officer corps was finally in a position to effect the changes that they had envisioned and written about for twenty years. It wasn’t a moment too soon: the same day Marshall was sworn in, Germany invaded Poland.

In 1940, Marshall – remembering the poor performance of commanders in World War I – began the GHQ Maneuvers in the southern U.S. He called up National Guard divisions and paired them with Regular Army divisions to create full-scale army maneuvers: hundreds of thousands of men moving around Texas, Louisiana, and the Carolinas. Here he and other military leaders were able to evaluate new technologies, test new doctrine, and get a feel for whether commanders were effective or not. Many were not, and were relieved of command, probably saving many lives in the coming conflict. The entire maneuvers provided Marshall and other key leaders the informational snapshot that they needed in order to start building the Army to war footing. Just as the maneuvers were winding down in the winter of 1941, the Japanese attacked Pearl Harbor and the U.S. was at war again.

One of the first things that the War Department did in 1942 was to operationalize the National Guard. One of the key lessons from World War I was that the Guard was needed on the front lines, but that they needed a time to train up. The other move was to get rid of the 28,000-man monstrosity of a division. The Army’s divisions were cut down in size, made more agile and adaptive, and given greater lethality through the addition of more enablers. The Army got rid of the brigade and replaced it with the regimental combat team, composed of an infantry regiment, a field artillery battalion, and an engineer company. Infantry regiments gained antitank capabilities as well as their own organic artillery companies. These smaller and faster forces proved far more effective than their lumbering predecessors of World War I. The Army adopted a tank corps as well and began training for combined arms warfare. Although the Army was still behind the 8-ball when it entered combat in 1942, the results would have been far more disastrous had it not been for the efforts of the generation of officers who had lived through the Great War.

Another key take-away from World War I was building relationships with Allies. Marshall and Eisenhower were far more patient men than Pershing had been, and were able to navigate the diplomatic pitfalls of being an allied commander far better than someone like Patton or MacArthur would have. But Marshall did have his breaking points. For example, during a 1944 planning conference with the British, Prime Minister Winston Churchill was demanding an Allied invasion of the island of Rhodes, at which Marshall finally exploded, allegedly stating, “No American is going to land on that goddam island!” These outbursts were minimal, however, and the American and British coalition managed to stay together to defeat the Nazis and the Japanese.

There was one more way that World War I taught the U.S. people a lesson, and that was in the realm of veterans’ affairs. Between 1919-1920, the U.S. military sent millions of servicemembers back into civilian life. Many were wounded – both physically and mentally – and there was no real plan to take care of these “ex servicemen” as they were called at the time. Congress had passed a bill in 1924 granting a bonus to those who had honorably served during the war, but during the Great Depression the payouts had been

Police clash with Bonus Marchers (Wikimedia Commons)

cut back. In 1932, thousands of veterans descended on Washington D.C. in the infamous Bonus March. They were eventually evicted at gunpoint and with tear gas by Army units in one of the most shameful treatment of veterans in our nation’s history. MacArthur, Patton, and Eisenhower all took part in this execrable affair. With that living in recent memory, veterans services organizations and WWI veterans in Congress resolved that nothing like it should ever happen again. The Servicemen’s Readjustment Act of 1944 provided a whole range of benefits to veterans returning to society, the chief of which was access to a college education. This act is commonly known as the GI Bill.

From the battlefield to the staff room to the college campus, World War I veterans made their presence felt. While World War I would lead to World War II, it was American experience in the first that brought victory to the second.

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About the Author: Angry Staff Officer is an Army engineer officer who is adrift in a sea of doctrine and staff operations and uses writing as a means to retain his sanity. He also collaborates on a podcast with Adin Dobkin entitled War Stories, which examines key moments in the history of warfare.

4 Replies to “How Experience in WWI brought the U.S. Army to Victory in WWII”

Nice article. Another possible historical effect associated with WW1 could be that the inexperienced American army was likely underestimated at the time by the German military. A factor, perhaps in Hitler declaring war on the US, thereby letting (no foreign wars) Roosevelt off the hook from asking congress to declare war on a power that hadn’t actually attacked the US.

“Infantry In Battle”. It’s. The AAR on Infantry actions during WW1. Two important events occurred on June 6, 1944. The Invasion of Europe and Congress passed thr “GI” Bill. Which gave raise to the middle class.

The “Square” Division of WWI was designed to take heavy losses in combat and still have combat power. The Americans observed that the much smaller French and British divisions withered away to a staff and artillery after just a few days during an assault – the Square division was a direct result of that observation. The “Triangular” Division was a product of Marshall and technology. The Triangular doctrine started at platoon level (three maneuver squads that could be 2 up and on back, on up and 2 to flank or whatever) to the company (again 3 maneuver platoons) all the way up to division (3 maneuver regiments) so the same doctrine was applicable from 2nd LTs to MGs.